Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ 2,445	$ 1,658	$ 3,215	$ 718
OCI before reclassifications	2,732	1,358	1,770	2,546
Deferred income tax benefit (expense)	(582)	(283)	(380)	(533)
AOCI before reclassifications, net of income tax	4,595	2,733	4,605	2,731
Amounts reclassified from AOCI	19	(74)	7	(72)
Deferred income tax benefit (expense)	(4)	15	(2)	15
Amounts reclassified from AOCI, net of income tax	15	(59)	5	(57)
Balance, end of period	4,610	2,674	4,610	2,674
Unrealized Investment Gains (Losses), Net of Related Offsets (1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	1,867	1,551	3,066	564
OCI before reclassifications	2,865	1,278	1,356	2,500
Deferred income tax benefit (expense)	(602)	(268)	(284)	(525)
AOCI before reclassifications, net of income tax	4,130	2,561	4,138	2,539
Amounts reclassified from AOCI	23	(51)	13	(23)
Deferred income tax benefit (expense)	(5)	11	(3)	5
Amounts reclassified from AOCI, net of income tax	18	(40)	10	(18)
Balance, end of period	4,148	2,521	4,148	2,521
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	598	133	163	180
OCI before reclassifications	(139)	73	414	39
Deferred income tax benefit (expense)	29	(15)	(87)	(8)
AOCI before reclassifications, net of income tax	488	191	490	211
Amounts reclassified from AOCI	(4)	(23)	(6)	(49)
Deferred income tax benefit (expense)	1	4	1	10
Amounts reclassified from AOCI, net of income tax	(3)	(19)	(5)	(39)
Balance, end of period	485	172	485	172
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(20)	(26)	(14)	(26)
OCI before reclassifications	6	7	0	7
Deferred income tax benefit (expense)	(9)	0	(9)	0
AOCI before reclassifications, net of income tax	(23)	(19)	(23)	(19)
Amounts reclassified from AOCI	0	0	0	0
Deferred income tax benefit (expense)	0	0	0	0
Amounts reclassified from AOCI, net of income tax	0	0	0	0
Balance, end of period	$ (23)	$ (19)	(23)	$ (19)
Cumulative Effect, Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period			$ 3